Bleaching composition

ABSTRACT

A bleaching composition comprising an inorganic peroxide which releases hydrogen peroxide and a Beta -alkyllactone of the formula:   wherein R represents H or alkyl of one to 12 carbon atoms.

United States Patent [191 Nakagawa eta].

[ 51 Sept. 30, 1975 1 BLEACHING COMPOSITION [75] Inventors: Yunosuke Nakagawa, Koshigaya;

Shori Hakozaki; Koitsu Sato, both of Funabashi, all of Japan [73] Assignee: Kao Soap Co., Ltd., Tokyo, Japan [22] Filed: Oct. 18, 1973 [21] App]. No.: 407,591

[30] Foreign Application Priority Data Oct. 20, 1972 Japan 47-104974 [52] US. Cl. 252/186; 8/111; 252/99;

260/343.9; 260/610 A; 423/272 [51] Int. Cl. CllD 7/54; Cl 1D 7/18; DO6L 3/02 3,755,185 8/1973 Waldmumn et a1 423/272 3,775,332 '1l/l973 Heins et a1. 252/186 3,775,333 11/1973 Loffelman ct a1. 252/186 Primary Examiner-Benjamin R. Padgett Assistant Examiner-Irwin Gluck Attorney, Agent, or Firm-W'oodhams, Blanchard and Flynn 5 7 ABSTRACT A bleaching composition comprising an inorganic peroxide which releases hydrogen peroxide and a ,B-alkyllactone of the formula:

wherein R represents H or alkyl of one to 12 carbon atoms.

7 Claims, No Drawings BLEAC HING C OMPOSITION BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a bleaching composition,

- more particularly, an inorganic peroxide bleaching composition containing an activating agent for increasing the bleaching power of .the inorganic peroxide bleaching agent at low temperatures, i

2. Description of the Prior Art Inorganic peroxide bleaching agents such as sodium perborate generally exhibit a very high bleaching effect at high temperatures above 80C However, their bleaching effect at low temperatures, particularly below 40C, is very poor. Therefore, investigations have been made on improving the bleaching effect of inorganic peroxides at low temperatures and many activating agents have been proposed for this purpose. For example, British Pat. No. 836,988 teaches ester compounds, Japanese Pat. Publication No. 10165/1963 teaches compounds containing two or more acetyl groups bound to a nitrogen atom, U.S. Pat. No. 2,362,401 teaches organic acid anhydrides, U.S. Pat. No. 3,073,666 teaches alkyl phosphates and British Pat. No. 802,035 teaches nitriles, all for this purpose.

It has been considered that the prior art activating agents improve the bleaching effect, because they react with the inorganic peroxides in aqueous solution to form organic peracids which are more easily decomposed. In general, these activating agents per se have no bleaching effect and, therefore, it is preferred that they exhibit their activating effects when employed in as low a concentration as possible. Particularly, when the bleaching is to be effected at low temperatures, activating agents which are easily soluble in the aqueous bleaching liquor are desirable. When itis required to effect the bleaching at an especially low temperature within a short period of time, excellent solubility of the activating agent is quite important. Further, it is desirable that the activating agents per se and/or the organic peroxides formed in the bleaching solution do not emit an irritating odor.

SUMMARY OF THE INVENTION We have discovered'that B-alkyllactones'exhibit desirable activating effects for inorganic peroxide bleaching agents. They also are highly soluble in aqueous bleaching agent liquors and they do not emit an irritating odor. The present invention has been made on the basis of this discovery.

This invention provides a bleaching composition comprising an inorganic peroxide capable of releasing hydrogen peroxide in an aqueous solutiomand. a B-alkyllactone of the formula:

wherein R is H or alkyl of l12 carbon atoms.

,B-Alkyllactones can be prepared generally by react ing aldehydes with ketenes:

wherein R has the same meaning as above.

From the viewpoint of their solubility in the aqueous bleaching solution, preferred activating agents contained in the bleaching composition, of the present invention are B-alkyllactones of formula (1) in which R is H or alkyl of l4 carbon atoms. From the viewpoint of activating activity as well as solubility in the aqueous bleaching solution, an activating agent in which R is H, i.e., B'propiolactone, is especially preferred.

As the inorganic peroxides which are capable of releasing hydrogen peroxide in an aqueous solution and which are contained in the bleaching composition of the present invention, there can be mentioned hydrogen peroxide and compounds which decompose in aqueous solution to release hydrogen peroxide, such as sodium perborate, sodium percarbonate, sodium peroxypyrophosphate, sodium peroxysilicate and sodium peroxytripolyphosphate.

The propertion of B-alkyllactone to inorganic peroxide is most preferably such that the molar ratio of B-alkyllactone to hydrogen peroxide to be released in the aqueous solution is 1:1. However, this proportion is not critical. Generally, this proportion is from 10:1 to 1:10. In the practice of the present invention, the weight ratio of inorganic peroxide to B-alkyllactone is preferably in the range of 1:3 to 3:1 by weight.

The bleaching composition of the present invention is used generally in a concentration of about 0.001 to 3 wt.%, preferably about 0.01 to 2 wt.%, of inorganic peroxide in the aqueous bleaching liquor.

The bleaching composition of the present invention can be prepared in advance or immediately before the use. If necessary, a surfactant, a neutral or alkaline inorganic builder or other additives can be incorporated therein. As surfactants, there can be mentioned, for example, anionic surfactants such as sodium alkyl sulfates of 10 to 20 carbon atoms, sodium salts of higher fatty acids of 10 to 20 carbon atoms, sodium alkylbenzenesulfonates containing an alkyl group of 10 to 20 carbon atoms, sodium salts of polyoxyethylene alkyl ether sulfuric esters containing an alkyl group of 10 to 20 car bon atoms and sodium salts of polyoxyethylene alkylphenyl ether sulfuric esters containing an alkyl group of six to 10 carbon atoms; or nonionic surfactants such as polyoxyethylene alkyl ethers containing an alkyl group of 10 to 20 carbon atoms and polyoxyethylene alkylphenyl ethers containing an alkyl group ofsix to 10 carbon atoms.

As the neutral or alkaline inorganic builders, there can be mentioned, for example, sodium sulfate, sodium carbonate, sodium bicarbonate, polyphosphates such as sodium pyrophosphate and sodium tripolyphosphate and sodium silicate.

As other additives, there can be mentioned carboxymethyl cellulose, fluorescent dyes and perfumes.

It will be understood that the adjuncts used in the bleaching composition of the invention can be selected from among those conventionally used for this purpose in accordance with conventional practice. Since the present invention does not concern any discovery relating to such adjuncts, further description of them is believed unnecessary.

The present invention will be further described by reference to the following illustrative examples, wherein parts" refers to parts by weight.

3 EXAMPLE 1 0.5 Part of each activating agent'listed in Table 1 was added to a bleaching solution consistingof 0.5 part of sodium perborate and 0.1 part'of sodium laurylsulfate dissolved in 100 parts of ion-exchanged water. Directly thereafter, a soiled cloth for the bleaching test was immersed in the solution and kept at C for 20 minutes. Then, the bleached cloth was washed with water and was air-dried. The reflectivity of the thus-treated cloth was determined with a spectrophotometer at 550 mu. The bleaching power was determined by the difference in reflectivity between the thus-treated cloth and the originalfsoiled cloth.

The soiled cloth for the bleaching test was prepared by boiling a cotton cloth in black tea, followed by airdryirig, washing with water and ironing.

4 concluded that the test piece treated with the bleaching solution containing B-propiolactone had a higher whiteness than the other test piece.

EXAMPLE 4 30 Parts of B-propiolactone were added and adsorbed to 70 parts of colloidal silica powders. Parts of this adsorbed mixture were mixed with 25 parts of sodium percarbonate, 25 parts of sodium tolypolyphosphate and 25 parts of sodium sulfate to obtain a bleaching composition in a dry powder form. 2.0 Parts of this bleaching composition were dissolved in 100 parts of ion-exchanged water. The bleaching power of this solution was determined by the same method as described in Example 1. It was 21.0.

As will be seen in the above Examples, the composition of the present invention is available not only as none(control) It is apparent from the above table that the activating agents of the present invention No 7 to No. 9 have an excellent activating ability.

It is not easy to employ acetic anhydride (No. 1 because it has a strong irritating odor.

EXAMPLE 2 0.5 Part of ,B-butyrolactone (invention) or 'y-butyrolactone (control) was added to a bleaching solution consisting of 0.5 part of sodium percarbonate and 0.05 part of sodium dodecylbenzene sulfonate in 100 parts of ion-exchanged water. Directly thereafter, the same soiled cloth for the bleaching test as employed in Example l was immersed in the solution and kept at 40C for minutes.

The bleaching powers (increase in reflectivity) of B-butyrolactone and 'y-butyrolactone were 25.8 and 10.5, respectively. The bleaching power of the bleaching solution containing no activating agent was 10.6.

EXAMPLE 3 An underwear yellowed by use for a long period of time was cut into halves. One of the halves was immersed in a bleaching solution consisting of 0.1 part of hydrogen peroixde, 0.01 part of sodium salt of polyoxyethylene (2) lauryl e'ther sulfuric ester and 0.05 part of sodium tripolyphosphateand was kept at 10C for 30 minutes.

0.5 Part of B-propiolactone was added to the same bleaching solution as above. Directly thereafter, the other half of the underwear was immersed therein and was kept at 10C for 30 minutes.

Both of the thus bleached test pieces were washed with water and air-dried. A. test panel of 10 persons judged the test pieces by the naked eye The test panel aqueous solutions, but also in a dry powder or paste form.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A bleaching composition comprising an inorganic peroxide capable of releasing hydrogen peroxide in aqueous solution and a compound of the formula in which R is H or alkyl of one to 12 carbon atoms.

2. A bleaching composition according to claim 1, in which the inorganic peroxide is selected from the group consisting of hydrogen peroxide, sodium perborate, sodium percarbonate, sodium peroxypyrophosphate, sodium peroxysilicate and sodium peroxytripolyphosphate.

3. A bleaching composition according to claim 2, in which R is alkyl of one to four carbon atoms.

4. A bleaching composition according to claim 2, in which R is H.

5. A bleaching composition in which the proportion of said compound to said inorganic peroxide is such that the molar ratio of hydrogen peroxide to said compound, in an aqueous solution of said bleaching composition is from 10:1 to 1:10.

6. A bleaching composition according to claim 5 in which said proportion is such that said molar ratio is about 1:1.

7. An aqueous bleaching liquor comprising an aqueous solution of the bleaching composition of claim 1 and containing from about 0.001 to 3 wt. 71. of said inorganic peroxide. 

1. A BLEACHING COMPOSITION COMPRISING AN INORGANIC PEROXIDE CAPABLE OF RELEASING HYDROGEN PEROXIDE IN AQUEOUS SOLUTION AND A COMPOUND OF THE FORMULA
 2. A bleaching composition according to claim 1, in which the inorganic peroxide is selected from the group consisting of hydrogen peroxide, sodium perborate, sodium percarbonate, sodium peroxypyrophosphate, sodium peroxysilicate and sodium peroxytripolyphosphate.
 3. A bleaching composition according to claim 2, in which R is alkyl of one to four carbon atoms.
 4. A bleaching composition according to claim 2, in which R is H.
 5. A bleaching composition in which the proportion of said compound to said inorganic peroxide is such that the molar ratio of hydrogen peroxide to said compound, in an aqueous solution of said bleaching composition is from 10:1 to 1:10.
 6. A bleaching composition according to claim 5 in which said proportion is such that said molar ratio is about 1:1.
 7. An aqueous bleaching liquor comprising an aqueous solution of the bleaching composition of claim 1 and containing from about 0.001 to 3 wt. % of said inorganic peroxide. 